Semiconductor device and method for manufacturing the same

Abstract

A semiconductor device which includes an oxide semiconductor layer, a source electrode and a drain electrode electrically connected to the oxide semiconductor layer, a gate insulating layer covering the oxide semiconductor layer, the source electrode, and the drain electrode, and a gate electrode over the gate insulating layer is provided. The thickness of the oxide semiconductor layer is greater than or equal to 1 nm and less than or equal to 10 nm. The gate insulating layer satisfies a relation where εr / d is greater than or equal to 0.08 (nm−1) and less than or equal to 7.9 (nm−1) when the relative permittivity of a material used for the gate insulating layer is εr and the thickness of the gate insulating layer is d. The distance between the source electrode and the drain electrode is greater than or equal to 10 nm and less than or equal to 1 μm.

Description

TECHNICAL FIELD

[0001] The technical field of the present invention relates to a semiconductor device and a method for manufacturing the semiconductor device. Note that semiconductor devices herein refer to general elements and devices which function by utilizing semiconductor characteristics.BACKGROUND ART

[0002] There are a wide variety of metal oxides, which are used for various applications. Indium oxide is a well-known material and is used as a material for transparent electrodes which are needed for liquid crystal display devices or the like.

[0003] Some metal oxides have semiconductor characteristics. Examples of such metal oxides having semiconductor characteristics include tungsten oxide, tin oxide, indium oxide, zinc oxide, and the like. A thin film transistor in which a channel formation region is formed using such a metal oxide is already known (for example, see Patent Documents 1 to 4, Non-Patent Document 1, and the like).

[0004] Not only single-component oxides but also multi-...

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